Organic electroluminescent display devices including a substrate which has light emitting devices each controlled independently and provided in accordance with pixels, and also including a counter substrate located to face the substrate, in which light emitted by the light emitting device in each pixel is visually recognized through the counter substrate to provide information display or the like are now being developed. Such an organic electroluminescent display device is of a top emission type, and in the case where light emitted by the light emitting device is so-called white light, the counter substrate includes a color filter.
In an organic electroluminescent display device that provides color display, one pixel includes, for example, a red pixel, a green pixel and a blue pixel. The light emitting intensity of the light emitting device of the color pixel of each color is changed in one pixel, so that the color tone is changed to provide color display. Therefore, the red pixel, the green pixel and the blue pixel included in one pixel are each referred to also as a “sub pixel”.
The color filter is provided over the side of the pixel on which the light is output from the light emitting device. In the color filter, color layers (color filter layers) having different transmission spectra are defined in correspondence with the sub pixels. At a border between the color filter layers having different transmission spectra, a light shielding layer is provided.
The light shielding layer is provided in order to demarcate the sub pixels having different color elements so that color mixture which would otherwise occur between adjacent pixels (or sub pixels) is prevented. For example, Japanese Laid-Open Patent Publications No. 2002-299044 and Japanese Laid-Open Patent Publications No. 2007-220395 each disclose an organic electroluminescent display device in which a light shielding layer is provided to enclose a light emitting area of each pixel in order to prevent light leaks between adjacent pixels (sub pixels).
Recently, electronic devices including a graphical user interface which displays an image such as an icon or the like on a display screen and is operated by a touch on the image have been widely used. A display panel also having as an input function that is used in such an electronic device is also referred to as a touch panel (or touch screen). A mainstream touch panel is of an electrostatic capacitance system, which detects a change in the electrostatic capacitance of the sensor electrode and converts such an electrostatic capacitance into an input signal.
Japanese Laid-Open Patent Publication No. 2008-216543 discloses an organic electroluminescent display device having such an input function. In this organic electroluminescent display device, a part of the sensor electrode that detects a touch also acts as a light shielding layer.
The light shielding layer disclosed in each of Japanese Laid-Open Patent Publications Nos. 2002-299044 and 2007-220395 is provided only for the purpose of shielding light. In order to provide such an organic electroluminescent display device with a touch input function, a touch panel of an electrostatic capacitance system needs to be externally attached thereto. An organic electroluminescent display device having such an externally attached touch panel is increased in the size or the thickness and in the weight, and cannot be applied for an electronic device that needs to be thinner and more lightweight.
In the organic electroluminescent display device disclosed in Japanese Laid-Open Patent Publication No. 2008-216543, the light shielding layer also acts as a sensor electrode. However, the part acting as the sensor electrode is separated from a lattice portion that blocks light. Namely, a part of the light shielding unit acts as the sensor electrode. In other words, the light shielding unit includes a sensor electrode unit acting as the sensor electrode and a unit that does not act as the sensor electrode and acts only as a light shielding layer.
Therefore, the part also acting as the sensor electrode in a touch detection zone needs to be separated from the part acting only as the light shielding layer. In such a separation area, light leaks. In the case where the light shielding layer, which originally should block light, has such a separation area, display lines are recognized due to a luminance difference or the like and thus image quality is deteriorated.